• Title/Summary/Keyword: Pressure Difference

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A Study on Dietary Intakes and Nutritional Status in College Women Smokers -I. Anthropometric Measurements and Nutrient Intakes - (흡연 여대생의 식이섭취실태 및 영양상태 평가에 관한 연구 -I. 신체계측 및 식이섭취실태 -)

  • 김정희;이화신;문정숙;김경원
    • Korean Journal of Community Nutrition
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    • v.2 no.1
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    • pp.33-43
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    • 1997
  • In order to investigate the dietary intakes and physical characteristics in college women smokers, interviews using questionnaires were done on 33 smokers and 42 nonsmokers residing in seoul area. General living habits, dietary habits, food consumption frequency and nutrient intake by quick estimation were investigated through direct interviews with subjects. Subjects height, weight and blood pressure were measured, and body fat percentage were statistically analyzed using Bio-electrical Impedence Fatness Analyzer(GIF-891). All data were statistically analyzed by SAS PC package program ; percentage or mean and standard error were examined for each item, and the significant difference was evaluated by chi-square test or Student's t-test at $\alpha$=0.05. In the analysis of taste and food preference, smokers consumed larger amount of alcohol and coffee than nonsmokers ; they also disliked sweet taste. The results of food consumption frequency data also showed that smokers consumed less fish, milk and fruits but consumed more instant foods than nonsmokers. As a result of anthropometric measurements, height, age, and 패요 fat percentage showed no difference, but there was a significant difference in weight, BMI, systolic blood pressure, and diastolic blood pressure. Energy intake in nonsmokers was 1640 ㎉/day(CHO : Pro : Fat=66.0 : 14.7 : 19.3), in smokers. Intakes of calcium, iron, vitamin C, vitamin A, vitamin B1, vitamin B2, and niacin in smokers were not significantly different from those of nonsmokers.

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Evaluation of Coefficient of Consolidation for Dilatory Dissipation Result of Piezocone Test (피에조콘 소산시험시 지연소산이 발생한 경우에 대한 압밀계수 평가 방법)

  • Ha, Tae-Gyun;Chung, Choong-Ki
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.1328-1339
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    • 2008
  • For a commonly used piezocone with a shoulder filter element, dilatory dissipation behavior, which shows an initial temporary increase in pore pressure, has been observed in overconsolidated cohesive soils. However, there is no appropriate way to estimate a consolidation parameter from a dilatory dissipation curve because currently available interpretation methods were developed based on the monotonic decrease of the excess pore pressure. In this study, the interpretation method for evaluation of coefficient of consolidation from a dilatory dissipation result of piezocone test was developed by performing the finite difference analysis on the dissipation after cone penetration. The distribution of the initial excess pore pressure induced by cone penetration, which is the core of the analysis, was estimated from the empirical modification of a solution proposed by cavity expansion theory and critical state concept. And the proposed interpretation method was applied to the field piezocone data and the results were compared to those obtained from laboratory tests. Its reliability was confirmed by the insignificant difference between the values of coefficient of consolidation from piezocone tests and laboratory consolidation tests.

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Gender differences in the relationship between adiposity and systolic inter-arm blood pressure difference in Korea adults

  • Kim, Gwang-Seok
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.11
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    • pp.113-120
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    • 2016
  • The present study was conducted to assess gender differences in the relationship between adiposity and systolic inter-arm blood pressure difference (sIAD) in Korean adults. In this paper, we propose a 410 adults (235 men and 175 women) who were over 30 years old and had undergone a health check participated from June to November 2013. The incidences of high sIAD (sIAD ${\geq}10mmHg$) in males and females were 24.6% and 15.3%, respectively. We conducted a logistic regression analysis after adjusting for variables such as age, smoking, drinking, exercising, TC, TG, HDL-C, and FPG. Key study results were as follows: First, in men, the odds ratio (OR) of high sIAD of the obesity group was significantly higher than that of the normal weight group [2.25 (95% confidence interval (CI), 1.19-4.25)], but abdominal obesity was not associated with high sIAD. Second, in women, the OR of high sIAD of the abdominal obesity group was significantly higher than that of the non-abdominal obesity group [2.52 (95% CI, 1.03-6.13)], but obesity status was not associated with high sIAD. In conclusion, Obesity is associated with the incidence of high sIAD in Korean men, and abdominal obesity is associated with the incidence of high sIAD in Korean women.

Experimental Study of Water Penetration Rate Via Graphene Oxide Membrane According to Driven Pressure Difference (산화 그래핀 맴브레인의 물투과 속도와 차압 조건 간 상관관계에 대한 실험적 연구)

  • Kim, Ji-Min
    • Journal of the Korean Society of Mechanical Technology
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    • v.20 no.6
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    • pp.858-864
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    • 2018
  • Graphene oxide (GO) laminate is a new promising material for water purification system, which has extraordinary permeability only for water molecule. It consists of numerous nano-channels, in which water molecules could be nano-confined, resulting in slip of the molecules for very fast transportation speed. In this study, water penetration rate via different thickness of GO membrane according to driven pressures are measured experimentally, so that speed of water molecules and permeability are evaluated. Generally, water penetration rate via a membrane with macroscopic-sized channel increases linearly with pressure difference between up and bottom side of the membrane, but that via GO membrane approaches asymptotic value (i.e. saturation) as like a log function. Moreover, the permeability of GO membrane was observed in inverse proportion to its thickness. Based on the experimental observations, a correlation for volume flux via GO membrane was suggested with respect to its thickness and external pressure difference.

Numerical study on pressure drop with moving contact lines of dry slug flow in a hydrophobic minichannel (소수성 미니채널 내 움직이는 접촉선을 가진 액체슬러그의 압력 강하에 대한 수치해석)

  • Jeon, Jun Ho;Park, Su Chung;Yu, Dong In;Kim, Tae Hun;Lee, Yeon Won
    • Journal of the Korean Society of Visualization
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    • v.18 no.3
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    • pp.116-121
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    • 2020
  • In this study, a single-phase analysis of droplet slug with different contact angles was performed based on the visualization of experimental results. Droplet slug - flowing between gases in a hydrophobic mini channel - moves with a triple contact line without a gas liquid film on the wall. The results show that the rotational flow inside the droplet occurred; this was compared and verified with the results of two-phase analysis. The pressure field shows pressure rise at the front and rear ends. The effective length - the section that satisfies the laminar flow condition - became shorter as the droplet velocity increased. The Choi's correlation for the effective length agrees with this analysis results with a slight difference. This difference is judged as the difference in the contact angle of the slug model.

Analysis of Correlation by Myopic Refractive Errors and Intraocular Pressure (근시성 굴절이상과 안압의 상관관계 분석)

  • Kim, Bo-Yun;Lee, Eun-Hee;Jung, Mi-A
    • Journal of the Korea Convergence Society
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    • v.11 no.8
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    • pp.317-321
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    • 2020
  • This study researched the correlation between myopic refractive errors and intraocular pressure. The study population comprised 39 adults(17 of males, 22 of females). We measured the intraocular pressure using a Non-Contact Tonometer(NCT) and the correlation between myopic refractive errors was analyzed by dividing into three groups: mild, moderate, high myopia. The gender of subjects showed no statistically difference between the intraocular pressure and refractive errors, but as the refractive errors increased, the intraocular pressure incereased, which showed a statistically significant difference. In addition, the higher intraocular pressure in moderate and high myopia than mild myopia can cause glaucoma, that can develop at a young age. it is need to sufficient recognition and understanding correlation between intraocular pressure and myopic refractive errors in the middle-aged high myopia.

Effects of Exercise and Calcium intake on Blood Pressure and Blood Lipids in Premenopausal Women (폐경전 성인 여성에서 운동과 칼슘 섭취량이 혈압과 혈중 지질에 미치는 영향)

  • 최미자
    • Journal of Nutrition and Health
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    • v.34 no.1
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    • pp.62-68
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    • 2001
  • The purpose of this study was to confirm that regular physical exercise habit and calcium intake play a role reducing the risk of cardiovascular diseae, particularly to confrim that regular exercise is important in reducing serum lipid levels. Subjects were classified into regular exercise group(more than 3 times/wk, more than 30 min per exercise) and non-regular exercise group. A convenient frequency method was used to assess the nutritional intake of subjects. Anthropometric measurement such as bodyweight and hight, and blood pressure were measured. There was no significant difference between nonexercisers and exerciser in energy intake, calcium intake and blood lipid levels. The strength of frequency of exercise may not by adequate to modify lipid profiles in premenopausal woman with normal lipid level, Although we found no significant difference in blood lipid levels, this result does not imply there are no benefits of exercise subjects. There were no signigicant correlations between age or weight with blood lipids in regular exercise group, while there were significant positive correlations between age of weight with blood lipids in non-regular exercise group. The levels of serum cholesterol, and triglyceride, blood pressure and atherogenic index increased with age in nonexercise women, Especially, atherogenic index was lower in regular exercise group. The blood pressure in nonexercise group was significantly higher than that in regular exercise group There was a highly significant negative correlation between calcium intake and blood pressure in nonexercise women, There was a highly significant negative correlation between calcium intake and blood pressure in nonexercise women. The results suggest that increased habitual physical activity and calcium intake may have desirable effects on serum lipid levels and blood pressure in premenopausal women.(Korean J Nutrition 34(1):62-68, 2001)

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Comparison of Friction and Wear Characteristics of Thin Film Coatings Using Tribotesters at Atmospheric/Vacuum Conditions (대기압/진공 조건의 트라이보 시험기를 이용한 박막 코팅의 마찰/마모 특성 비교)

  • Kim, Hae-Jin;Kim, Dae-Eun;Kim, Chang-Lae
    • Tribology and Lubricants
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    • v.35 no.6
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    • pp.389-395
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    • 2019
  • In various industries, thin film coatings are used to improve friction and wear characteristics. Various types of tribotesters are used to evaluate the friction and wear characteristics of such thin film coatings. In this study, we fabricated a micro-tribotester and Tribo-scanning electron microscopy (SEM) to compare the friction and wear characteristics of copper (Cu) coatings under an atmospheric pressure and a vacuum condition, respectively. The reliability of the different types of tribotesters was evaluated by performing calibrations for the sensor to measure the friction forces and normal loads. Using the two different types of devices, the friction and wear tests are conducted at the same experimental conditions excluding environment conditions such as the atmospheric pressure and vacuum condition. The friction coefficient at the vacuum condition is lower than at the atmospheric pressure. This difference in friction characteristics is due to the fact that wear phenomena occur differently according to the atmospheric pressure and vacuum condition. At the atmospheric pressure, the abrasive wear is the main wear mechanism. At the vacuum condition, the adhesive wear is the main wear mechanism. The reason for the difference in the wear mechanism of the Cu coating at the atmospheric pressure and the vacuum condition is that the oxidation phenomenon, which does not appear at the vacuum condition, occurs at the atmospheric pressure; therefore, the characteristics of the Cu coating change accordingly.

A Study on Impact of Squat Exercise on Foot Pressure with different loads (스쿼트 운동 시 발의 압력에 미치는 영향)

  • Won, Hyo-Heon;Kim, Min-Wook;Bae, Yeong-Hun;Kim, Yong-Jae
    • Journal of Fisheries and Marine Sciences Education
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    • v.25 no.4
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    • pp.891-897
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    • 2013
  • This study is purposed to propose indices in order to achieve goals such as preventing one-sided movement of balance, preventing injuries to joints of legs, improving muscular strength of legs, and maximizing sporting achievement. In terms of methodology, this study has compared foot pressure distribution during squat exercise. This study targets 10 male students in their 20s of Department of Physical Education and 10 male students in their 20s of other departments of P University located in B City. Skilled members have been selected out of those who have had regular weight training experiences for last 3 years. As a result of analysis on impact of squat exercise on foot pressure, conclusions have been obtained as shown below. As a result of analysis on foot pressure distribution of back feet of skilled members and unskilled members during squat exercise, it was found out that foot pressure of left foot of skilled members was 0.13kgf/s, and that of unskilled members was 0.28kgf/s, showing significant difference (p<.01). As a result of analysis on foot pressure ratio of back feet of skilled members and unskilled members during squat exercise, it was found out that foot pressure ratio of left foot of skilled members was 50.03%, and that of unskilled members was 67.18%, showing significant difference(p<.01).

Effects of One-time bamboo stepping on the Elderly's Blood Pressure and the Autonomic Neural System (일회성 대나무 밟기가 노인의 혈압과 자율신경계에 미치는 영향)

  • Jeon, Do-yeon;Yun, Hui-young;Kwon, Eun-pyo;Son, Hee-su;Goo, Bong-oh
    • Journal of Korean Physical Therapy Science
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    • v.26 no.2
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    • pp.32-37
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    • 2019
  • Background: The purpose of this study is to investigate the change of blood pressure and autonomic neural system through one-time bamboo stepping in hypertensive elderly people. Design: Randomized Controlled Trial. Methods: We recruited 26 elderly people aged 65 or older for study. They sat for 10 minutes in a chair, rested, and measured pre-exercise blood pressure and autonomic neural system. The blood pressure was measured three times and the mean value was used and the autonomic neural system was measured once. Bamboo stepping exercise was performed for 20 minutes. Blood pressure and autonomic neural system were measured 5 times immediately after exercise, and every 15 minutes at 60 minutes after bamboo stepping exercise. Results: There was a significant difference in the decrease of systolic blood pressure after one-time bamboo stepping exercise, the change of parasympathetic activity (HF), heart rate variability (HRV) and BPM measured immediately after exercise at 15 minutes after exercise, There was no significant difference in autonomic neural system change. Conclusion: One-time Bamboo stepping exercise is effective in decreasing systolic blood pressure of the hypertensive elderly.